1. Technical Field
This invention generally relates to an apparatus for opening and closing of railroad car doors, and more specifically to an apparatus for automatically or semi-automatically opening and closing rapid discharge railcar doors located on or near the bottom of a railcar.
2. State of the Art
A common type of railroad freight car used today is an open-top hopper car wherein the commodity carried by the railcar is discharged through an opening provided on the underside of the car. Such cars are used to haul aggregate, iron ore, coal and other commodities. Such cars offer an advantageously economical method of transporting large amounts of a commodity between locations.
Such railroad cars generally include a walled enclosure or hopper carried by an under frame of the car. On some hopper cars, the under frame includes a longitudinally elongated center sill or support which is supported, toward its opposing ends, by the usual wheeled trucks that ride on tracks or rails. Although the design of the bottom side of the railcar hopper varies considerably, the hopper is typically provided with a plurality of generally funnel shaped discharge openings which extend either parallel to the longitudinal axis of the car (longitudinal openings) or are disposed in pairs on opposite lateral sides of the longitudinal axis of the car (transverse openings). Each type of hopper serves a particular need in the railcar industry.
Conventionally, when a hopper car arrives to deliver its load, technicians open its doors. The conventional way to open the door is by striking the railcar door latch in an upward direction with a large sledgehammer. The striking motion required has to be accurate for the latch to move to the open position. Often, it takes multiple strikes of a hammer for the latch to release, allowing the doors to open and dispatch the material into the hopper below.
The technician opening the door in this conventional way is exposed to many hazards. The surface he is standing on, through which the transported commodity falls, is generally a grate of various dimensions of spacing; an estimated average is an opening of approximately six inches square. The grate is necessary for the material to flow through to a hopper located under the grate. The grate creates a hazard for the technician, and the industry has experienced an unacceptably large number of accidents related to human extremities slipping through the grate while technicians open the doors. Additionally, missing the latch while attempting to deliver the powerful strike required to move the latch can result in the technicians loosing their balance, falling and sustaining various types of injuries.
To close the doors the technician again stands on the grate through which the material flows. While on this grate, the technician is required to use a heavy steel bar, which is inserted into the hopper door, and then pried up to the latch of the railcar door latch. When the hopper doors are bent or out of square, which is common due to the fact that the doors are generally opened one side at a time causing torsional stresses on the door from the weight of the commodity above the door, the technician is then required to force the doors closed in anyway possible. This action while standing on the grate creates a hazard for the technicians, and the industry has experienced an unacceptably large number of accidents related to human extremities falling through this grate while technicians close the doors too. Many injuries to the back are also sustained.
U.S. Pat. No. 4,508,037 to Rousseau describes a car door opener for use on a railway hopper car with several rapid discharge bottom dump doors. In Rousseau, the doors are operated by a main door-operating member in the form of a truss bar running the length of the car. Moving of the bar rotates levers; the rotation of the levers rotates actuator shafts; the rotation of the actuator shafts move the door operating linkage arrangements resulting in opening and closing of the dump doors.
U.S. Pat. No. 4,843,974 to Ritter describes a car door opener for use on a railroad hopper car having bottom discharge doors. In Ritter, an elongated beam assembly along the bottom of the car, door operating levers to open and close the doors connected to the beam assembly and doors, and lost motion timing connections in the beam assembly which permits displacement of beam sections to open and close pairs or sets of doors in a sequential but substantially simultaneous and automatic order so as to permit reduction of air pressure required to open the doors, or permit use of smaller diameter air cylinder.
U.S. Pat. No. 5,419,262 to Turpin describes a closer. In Turpin, the hopper car doors including a supporting frame structure associated with the rails on which a series of hopper cars are rolling supported together with power actuated devices that will pivot the hopper car doors from a generally vertical, downwardly extending open position which exists after the hopper car has been unloaded for engaging the hopper car doors and pivoting them about their transversely extending supporting axis to a closed, latched position. The power devices include transversally extending support shafts with a pair of laterally extending rigid arms, with each arm including a wheel at its outer end for engaging the hopper car doors when the transverse shafts are pivoted.
U.S. Pat. No. 5,299,508 to Connelly describes a railroad car door closure having trackside mounted plural actuating arms. In Connelly, a closer for closing the doors of a railroad hopper car has two closer assemblies. The assemblies are mounted adjacent to each rail of a track on a frame, which passes below and between the rails. Each assembly includes a hydraulic closer jack, a hydraulic lifting jack and a hydraulic swing motor for orienting the closer jack related to a door. The jack is extendable to contact a door and push it to a closed position. The jack assemblies can be pivoted 180 degrees by the swing motor to close the door of the forward car and then rearward car without having to reposition the train.
U.S. Pat. No. 4,120,412 to Miller describes a trackside door closing arrangement for railway hopper cars. In Miller, a trackside door closing the swinging doors of a railway hopper car includes a pair of pneumatic tires and wheels mounted on a pivot arm. The tires are interconnected for rotation in concert and during engagement with the doors swing them inwardly to a closed position.
U.S. Pat. No. 4,011,956 to Green describes a closure mechanism for bottom dump hopper cars. In Green, a side of track closure mechanism is provided for engaging and exerting an inward direction lateral thrust against bottom dump doors of a hopper car for hingedly moving the doors inwardly directed lateral thrust against the doors moving the doors to a closed position. The actuating mechanism includes a rotating arm having actuating apparatus at one end which when placed in an index position is adapted to engage the doors of bottom dump hopper cars as they move along a track adjacent to which the closure mechanism is positioned.